SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fdec6e66cec17dde91b094f926e3aa5d9e9036badef035f7ea962a6327349af9' 
  AND token = 'KEfpiEnd2IrwJ8SdAG+zIDG89GdCAG54bcBd1PK5lCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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