SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba3e21161df2f2e5940fc07f5402cab740586b6c1b89439aa9cd2a953d7be6f1' 
  AND token = 'Fox4sJtwwnddH7t8ETHJN7bxF24lnBCDc+nEIEccslo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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