SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e360f4f78dd290bba842cbd5e4d351b399f5a7f2dfff701fe57a69f14653f50b' 
  AND token = 'Qpx7yc54sD4hXRg4k8Te6p+FWzO36j4My9u51iyGUjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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