SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f6a97c512235f50087e87b6685e544f04471385c583a16c95ae299e597348771' 
  AND token = 'SLqqjKunOhXBMpH7X3de0M8rzkHDty+G8OgDoNQfcCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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