SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71a7ce3816023fad66d9352ceb3480c426d1d0db304b8b98b68b691c9088f882' 
  AND token = 'wpifCNXeZl+R4Tu+OUyjjhGpUWQNyuIQkU/7GH2KgiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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