SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88e2a214b3f36137d2bb843c8b8d9ffb86bfc0c6c44e1ec7b82acf914770e41f' 
  AND token = 'lI6jRXCtzaxLnUweZBVkH/h4IUEq/Wu9BWd35FG7Jr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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