SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ea2a316c33d2a839cb78c8132c45293703e1b9621249bc419ebe1f3ef3b203d' 
  AND token = 'WByIv5whEDJ18fd1ZU8OeiKOqeBUPuMl6XxjnzLBikE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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