SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4463a4b499801c65386d64ac7441b04a60f0f211d414ce8067ad78679da9c3c' 
  AND token = 'gg1XaSkxCW96zQRAIxHFE94P4WYMA4dF8sh99rxceac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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