SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9e2c22a978dfd72e3e63980926964268049a8021aceb2a01ccf858fc5d16fcfd' 
  AND token = '8WIdOUJkrb2ArPp96zE7+t/L7xga2hsFKRjp064Tcqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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