SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2ad388a5da57d45a85a83ecd9861c55c17c857205b5e63fc54228b71560f4bf' 
  AND token = 'zO8EnIlP/i6uBzAo0f20yxkb7VwnwI9WdBH3pShsCjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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