SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '980f75faba0509da9c295aec9ef592c0b96b7249dcfc176bc1940dd062a4242b' 
  AND token = 'qubYfjOfQ6Ui/iIdw7KiRxN78GTyVIxEzx8t/bcdXUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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