SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4eaf3275eba1935a8dd1220cc9acf09ad9b5a34bda78c8e899de9e2c9d5c599a' 
  AND token = '0QsOnFcIUuVy6hnbfa7N2n52d2SCbgZ37v4GQ4lfUqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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