SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef56a49933c9fb0eef8df1075e577cc9a71014126adc0a504004c697945140be' 
  AND token = 'lv6XR8gNWEPNLPEn4/Y0wewOKms75pcWbCzUMsHdcM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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