SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'efd8868f022846acbcfec3ac27b7c4fc7b701e603012d003d7511d1afa821c35' 
  AND token = 'cf/7E/BbkJZa2bllq3zuWFCPRNJyEpgzQmrZj7XW+SU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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