SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fc156ab4bce3bb9d34631298c0e13c63afc7d6583ce782aabd45083998e9c14' 
  AND token = 'ItmuQx9KkW4H7jO1obKCziKJono3EfHra7PhEPLGcVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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