SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88c72f452081447d7289ad043e00a634766b97d0f96b0097d45ee5dadec22f7e' 
  AND token = 'c6Knh7fIuT4CSaln3aYdDsXJqEIGg+qeX4gLZnJxOqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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