SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3ab2ed1dfddf9d25c27062de1ae982fbbcc11428ca50615cb6c61f0bba1720e' 
  AND token = 'yoLcVaSkX4Rp+gTqn/7JH2UUQDokcxrh/StiF4Ow9Ho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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