SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4242304e4905200ec0ea79244862de441da20784a869f64183bbda45036792bd' 
  AND token = 'qOR1TRCtbZmOX3f8aCLks1Mu/9e1cHRVeAHFmn016tY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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