SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78ab644284da5cdcdf40bcd7afcc2bf8acfcfe9bfd8b9606372360e660a86201' 
  AND token = 'jx8RBDEOOgoLl0+bJ35DQKh0ExaHTjU7sfzp2nuzN7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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