SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1f9628fc8f372b74ff29adf13cb8ce65713de2492fb444359e661ae420e2a8b0' 
  AND token = 'PRQXKvtcHXiIM+Eg4K3Nw6RVqtD7pwwr4B0LDWvp+Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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