SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ed29382721ae221569ae5d19527472d0ddc8497f61388c019cd1535672fbcd5' 
  AND token = 'MeCIO+rZpT+5mum2McKRasSN8s/PO16U91sZLjwMoXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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