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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0d37e08c99c69c5b3dea7e9a796d65e25e64e3f8e9a45ae6a9063b5d47c4284' 
  AND token = 'N9P9RFdJCRkKIEw5IrWzqNwppuGJayPLNKGzbeKQYiA=' 
  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"
    }
  }
}