SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4eb64c84b629fca2e91698f3cc49fe7d3e54f5a060b26bf1c8bc5df1bba641e0' 
  AND token = 'LwRGxhBaO/fQq3/uep4+9e4XXKGLfq4JIMeI4JJU9As=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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