SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5a795337164c5d71d63fd2d54ae06a32a9975d4e389ce20bbea13072f407968' 
  AND token = 'H86sHUHIXYPHVqdF4ww3KOkGRNNfZCDhV2JqdZpBp6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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