SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8592c9e8e34630a5693710c3cf31fb25cbbf3c3bbb7ddf99f1c42753ecaf83b5' 
  AND token = 'KRFtXuwtL82AUVxb0N4pqfmFf/mga8LKHyp45XRnTVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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