SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd98782c2863e7d180c0b21a06afe2537df7ebdc0378e7fc742e888b2c8ea97ed' 
  AND token = '8gnGaBj9H/Hqo1+ugrRM1CWhTJtowE5KsqC8boqxhHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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