SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8748c143ae250cd4164dc07acc403968b66bb6f575ec98026c48e8b1301d915e' 
  AND token = 'GLaZhhQguRjSJxnnszmuX5xZBlJWDpDz7CVJPKD4VCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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