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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1989a484b5eda4c52921798ba2ecadc09fa2472750a53e4198d2289c0a9a5a99' 
  AND token = 'XqjrrSsjzWn4V37ATazr4c8qazDsF/w4WQgYVysvOQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}