Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac39dfde036c7d88831d560a70c1eb990c4b00124be35cf78fa14b1402c2796f' 
  AND token = '3mqHdr37cs7bbBgHSqzC1+QRB+OwpA+GZ5SQvDWZSG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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