SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17a56d0affab1c16604a6818f4e08e69539cde761b192342cb443bfc88709d72' 
  AND token = 'Se3WVDFgZAQY6Hg5UCEIyn6lQUb/ovvnIUl5SjdEpQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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