SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d48a1746a96f862f1cde6d841beaa557eb08cc626eaeae2dcffa30e98213edc' 
  AND token = 'SEuYWsWNQ39rmuspjtkrasV+iiL+lCSL24thU4DQwBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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