SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49b74af1ec3bbb16c940497aec14ba6202be4db54fc93453e80aacbcadd01da2' 
  AND token = 'i6jlrH7G5S4pJRjVVKyMVTId/Y02le2XcGWaV+EOjKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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