SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd567383ecadd561c9043074d30532e8fcf2408b6b5751d08473354e0433c0acd' 
  AND token = 'y1j7nhaeZLxdfIZWN+9vfTUY5yQC8gPs8CkGVbVbLhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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