SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecb8a823213fb98b58d86e95c258bdbf059d4055efc071487580a7b51f163666' 
  AND token = 'Huq07MuwXZh9yL/kRRyNYzMf5+C+0mGsS4O6uKqyFcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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