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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dcd668ea2388a47fe62bba989928de75fc1ccffda974070bdd6dbf9e1be3ef4d' 
  AND token = 'bauWHkqmyIfcEjIO1d5ZqDY5MjZUM42XoCkOLRXbOW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}