SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9956677ec9cab02b7bcf59a3c8cc967175c460bce65a56966a5c2a798870a30' 
  AND token = 'fdSHQoAs1oNhCMWaeDkZ0LkhXzD+ji9ak/x67XjDwXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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