SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36ba5ac9263cfb42bc7bdab4d4896c9b36d56dc8521f2bfbc6dd504d36cf736b' 
  AND token = 'OHrvNrKB0Fd82a79vBIWZU89eBQxFsRdUXDetaCuQk8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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