SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccd1b236b3f272c8af9ee58df15b66c10f797cd35c0666da75e2526076f9cf06' 
  AND token = '92m3R6w22I5zqkC9OYkHde/tLbeLTRvccr51zRAik44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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