SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '931df26ccc558e14c9a2b8c17ea05cb58060e5f680f1109162f101da1218fc28' 
  AND token = '2j1WumdtSY8RhPTDXpAtzxUBTbdmF++Obuax2RfCEIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}