SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '499c66d00d21e9402acd72bbab333a5bd58a6636c75aae2c576ba9c9af546198' 
  AND token = 'B1jRmwELv7aCYQHVmT8o37fvpW/cdhJWUpjHO6ym1yw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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