SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '800dd507db3ec02b2f055cfd4a0f543d4b9ef1bc1b571fc1ad615cd457f47567' 
  AND token = 'Pd3xkI//pErmEKsXwZ2nE42KPg59K5+iDkq4Jq6sPsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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