SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '356b86d36ec523c7e15f3cb167b3c3d1351d977b3d7a001b549aba0fbb23dc05' 
  AND token = 'V1zwIFtGD+cxxwrcKRyCW1NfldCw5j5Dmc+EFAOz8nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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