SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4f279bef18897e15ad367ed98c0892e0a226d7f69963212b3a5f7ebd4281cb02' 
  AND token = 'LE4T+kAgIFxzMtBK8QbO3VXNn3ubpIB/BaOoHpflN94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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