SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '277f6ad1e1bd32700a70585c6c16181df356e9896f20b839e695e2fe13ffa22b' 
  AND token = 'EnXeJsovN5COf5Gd+i9TN77nHwz/u6ar5Fcdtu0ekuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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