SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6064873dbdf3c3857b1edf91734f61607c4b520968960c2caf373b5bf28e448' 
  AND token = 'sIAXNJ1od6V4kvPCeSogqDCRd0gItGW2hCJUHlEjObY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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