SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '541cff3be02e8700827bbdc067aaf93c3fe257658637b609e8a064b3b8f6ef6b' 
  AND token = 'pX+yLBHnkm1wB6fF3kXx5fEtbgwKjiKqAqv2gzXuodw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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