SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a122bd08de49f31fe799052f41231f976c775a6afbf4e81f99243a15de44d5d' 
  AND token = 'SlHUlrYrSB0x9PfIIOvOHCNfdaB9qGgOx2e9Q/KTEEU=' 
  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"
    }
  }
}