SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19bdce48d556514535df2bbf34da2e0b5b6ae69a4df226f847647f9fb785bceb' 
  AND token = 'fkKtrJyuyrpAT4Q+Mpa7TxZ+4tifq7QkF9x4CJaRuqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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