SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1821bc08c549b110fcce700be2cb67097aa5c1ad42d032cb4ad0a3fff7e1907' 
  AND token = '5KyhfETKIxNeZ13NPN7mU2X1uod/ehh341wDlvyy6xQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}