SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da9356a600781ca72d175257b817fe7d9bf04da223e53a1dec2ffd70a564b0d5' 
  AND token = 'JTkAAxSmmsLf/2OuWAVVPwHpn98qoiKk7VEYnFVcOoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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