SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0ebf3d0671d54a7661fc9db24dfee22d409b018bac45ae2a5f6f0f39fce746d' 
  AND token = 'wIdsJddTnzmaiVNxZNBYrEUq5g4IQxiFx1jFGO/KmBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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