SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2372896cf4db14e2de88d40e1cd2037763bf738a864b8a05c604cd2168dee4cc' 
  AND token = 'M1e/+7+Zo5yfwXkyqRv6y52HxMyLJhSndBYji2KjBQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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