SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29251ea30e0af40e747a5c66f40f616a4bb069cb3824b79f9651dcdeac827578' 
  AND token = 'iAYVBX6sIc5HsErhrKqezci49VG3vJjI8VEfO4J/UQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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