SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0f4baedc3378f398630f576e8d602ec99d920f9727085500f61a403c704fc13f' 
  AND token = 'XGuOcq92+Ldykhs6gMWCFUroMdw4/jcVHuhdxzbbNYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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