SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19156563bc1a607072c6372f96efb1db153feb00868d84b1aba1bd8bdb8ca8c6' 
  AND token = '/K3GXCT1B3LpvTdgf7yTjs5SkXIwzrPVTg2+CnQrsqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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