SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dd115bbbb7fc3452cf25559a93c1c6527f65ce305f819a6d8fb4e3681739543' 
  AND token = 'R8ikgCyjPcaE/bYJggXDzEw9052+EZw/O/gyVIp48j8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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