SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7af20a8dd84b3b2b2592f8958e9d39673c50bb5a4b2c31d0160583614caf18a' 
  AND token = '8Szns7lvRiSFrMlTspcFVhBUwxvykIozfpA1LAM8i/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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