SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '607413614b5a933f0085cbf1b6d6363111383fd8f93ab029103ef04788aee755' 
  AND token = 'VEgRklvxFYqOdJRJZZjFm3hIl9JYRBg5RMqB14u3JGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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