SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f3f5b13b782950ffeb1b65a72d963ec7a0aa836dd31c6f4db729ce844d40252' 
  AND token = 'wmDKiDOmGQtQtZdXG49+qkODVul7HGZCMh7lTcblSNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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