SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '966829474ca22c9c98fc7a9342a252515ae9aacf43c80d021fc9bffb1d86747c' 
  AND token = '9Zf37jS6rPm0ICQMuRFwlrrk2QoNidgCqmZ8YZAdnCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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