SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45479482959d9d45a550ba009b7c03e7680cfe6c519374058a211cdd8217fe2b' 
  AND token = 'BSNyJ6FW4ZLXqXwhr3GFU8uQDvyDZTzCvAviiyUICQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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