SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bf5353d53796d8746c7aaf89c0276a6e360b84edaa5105c4616bdcfb76d956b' 
  AND token = 'DHOLZ2UyLQADepOrMpUFqIPKG1MDCh8X/AwInnpsjgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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