SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4092882275c308a78651ba07e43762c0bb931ce1b58acb2a8359c0e53c5f3ab6' 
  AND token = 'EFEmNCMQctl7MzyQ2wsEsJNKPTVwlojWfyr18TkOJo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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