SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccc919560c01981f048759ecc6a7c8eef14a6f078a5d7ed3dff9aabb9477c7a7' 
  AND token = 'kowZvWUdgTcB9paZ4Y4YyKYhuVjNlKKb0eToWOHhnFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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