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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fca53a1c65039758af124b8ecb9f3d11e0e5f9a19e51849bce1d50ac1a3f88c9' 
  AND token = 'MtNhQNMdZw/+i3Fd9w3pB4D4D++w2vtpmC+X9Plo/6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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