SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee342c3504acc5f95cf5b8fe9ba9d186b17700b92d37066e62108870a79cd4bd' 
  AND token = 'AMOPgzWbtirXegst5wWPs+MUlGHa5wzsjKLvCbkY7RE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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