SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4cb4aedd44c707aab2595f47b9f10b91380b1b348d0476770c29d36c2454645' 
  AND token = 'Y+9aeer3tYcM/Lq9p3iPsDFjoTFj/0PxTswE8FOzqxI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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