SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38fb993fd698f0a42008eb0195aa4006caef4c28ef42f6468e1772b76c19a736' 
  AND token = 'VwBXyQNTPkZ3xqu+N8extLzcT97OS3w7r8wNNWv033Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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